The present invention relates to oral hygiene appliances in general, and more particularly to improvements in so-called oral irrigating appliances. Still more particularly, the invention relates to improvements in oral hygiene appliances of the type wherein spurts or surges of water or a water-containing liquid are used for the cleaning of teeth, bridgework, crowns and orthodontic appliances as well as for invigorating the gums. In such appliances, spurts of water are produced by a motor-driven pump, e.g., a peristaltic pump or a pump utilizing a reciprocating piston.
In conventional oral hygiene appliances, the pressure of liquid which issues from the orifice of the nozzle (called jet tip) is regulated by way of the pump. In many instances, the pressure outlet of the pump is connected with the inlet by a conduit which contains suitable means for regulating the quantity of liquid that flows from the outlet back to the inlet. Such pressure regulating means are complex, prone to malfunction and rather expensive. Moreover, and if the pump comprises a reciprocating piston which receives motion from the rotary output element of an electric motor, the means (e.g., a crank drive) which converts rotary motion of the output element into reciprocatory motion of the piston is bulky, complex and expensive, especially since the dimensions of the pump and motor in an oral hygiene appliance are normally extremely small. Furthermore, presently known appliances are quite noisy and their useful life is relatively short.